The Minnesota Sports Facilities Authority said today it will unveil its design for the new Vikings stadium on Monday, May 13th.

The MSFA, the Minnesota Vikings and HKS Sports and Entertainment, the architect picked last September, have been working on the design for seven months now, and have put off the unveiling twice while they hash out the details of the so-called “schematic design.”

MSFA chairwoman Michele Kelm-Helgen says that the authority and architects still haven’t decided whether the roof will be retractable.

“There’s still a few moving pieces, no pun intended, but we haven’t actually finalized that decision yet,” Kelm-Helgen says. “But we will have it done by the 13th, so I think people are going to be impressed to see the facility. It’s really a beautiful building.”

She also says that it won’t look much like the preliminary renderings. “It really doesn’t.” She says she’s talked about the two initial options — the transparent roof and the “ribbon roof” design. “I always say the only thing we do know is that it won’t be this.”

But she suggests it’ll be a landmark.

“I think the design itself will attract a lot of attention, and I certainly think it will be very distinctive. I think it certainly fit in well with the Minnesota architecture that you see around. I think the design is going to be quite iconic.”

The MSFA will hold a special 7 PM meeting to unveil the design, which will then officially be presented to the city of Minneapolis. The city has a stadium implementation group looking at design and development issues around the site. The city will have 120 days for final approval. Architects will then work on construction and interior designs, among other things.

The Vikings are scheduled to play the 2013 season at the Metrodome, and the stadium is expected to be demolished soon after they finish football. Groundbreaking for the new stadium will start even sooner, likely in October, in the parking lot to the east of the Metrodome.

The Vikings will likely play the 2014 and 2015 seasons at TCF Bank Stadium at the University of Minnesota, and could start their preseason schedule in the new stadium in 2016, if construction is completed by July 1 that year, as planned.